The Gewehr 98 rifle was the final development in Mauser's line of turn-bolt rifles. First patented by Paul Mauser in 1896, it was adopted by the Imperial German Army in 1898. The Gew.98 action featured cock-on-opening, meaning that the cocking piece was forced back (and thus the mainspring compressed) by camming with an inclined-plane cut into the circular wall of the bolt body. Furthermore, the diameter of the receiver ring was increased by 1/8" (3.18mm), allowing the receiver to withstand greater chamber pressures.

The Gew. 98 incorporated several new safety features designed to cope with a burst cartridge. First, the receiver incorporated a ring of metal that would surround the bolt head between the locking lugs and the chamber face when the bolt was fully locked. This was to prevent the gasses from a burst cartridge from forcing the bolt head apart and traveling down the bolt raceway. The bolt body also had two large holes in the wall of the bolt, which allowed gasses from a breached primer to vent laterally out of the side of the bolt, rather than compressing and deforming the mainspring. In case the primary locking lugs gave way, a third locking lug was placed on the rear of the bolt body, which was designed to engage a recess in the bottom of the receiver and prevent the bolt from moving backward. In the event that burst gasses did escape into the bolt raceway, a large flange was designed into the front of the bolt shroud, which would deflect the gasses away from the shooter's face.

The design retained the 29.1" barrel of previous Mauser long rifles, but featured a new rear v-notch quadrant sight now known as the Lange-Visier. A very short handguard extended from the sight base to the lower barrel band, and the buttstock featured a pistol grip for more comfortable shooting. The Gew. 98 also featured a new bayonet lug projecting forward from the forend of the stock, which allowed the bayonet to be mounted closer to the centreline of the bore.

After World War 1, the Weimar Republic adopted the Gew. 98 for the 100,000-man Reichswehr allowed them under the Treaty of Versailles. The Lange sight was replaced with a conventional v-notch tangent-leaf sight, which would be retained on the later Kar98b, Mauser Standard-Modell, and the Kar98k. Other variants based on the Gew. 98 can be found on the Mauser Rifle Series page.